<?php
//=======================================================================
// File:        JPGRAPH_IMGTRANS.PHP
// Description: Extension for JpGraph to do some simple img transformations
// Created:     2003-09-06
// Ver:         $Id: jpgraph_imgtrans.php 1106 2009-02-22 20:16:35Z ljp $
//
// Copyright (c) Aditus Consulting. All rights reserved.
//========================================================================

//------------------------------------------------------------------------
// Class ImgTrans
// Perform some simple image transformations.
//------------------------------------------------------------------------
class ImgTrans {
	private $gdImg=null;

	function __construct($aGdImg) {
		// Constructor
		$this->gdImg = $aGdImg;
	}

	// --------------------------------------------------------------------
	// _TransVert3D() and _TransHor3D() are helper methods to
	// Skew3D().
	// --------------------------------------------------------------------
	function _TransVert3D($aGdImg,$aHorizon=100,$aSkewDist=120,$aDir=SKEW3D_DOWN,$aMinSize=true,$aFillColor='#FFFFFF',$aQuality=false,$aBorder=false,$aHorizonPos=0.5) {


		// Parameter check
		if( $aHorizonPos < 0 || $aHorizonPos > 1.0 ) {
			JpGraphError::RaiseL(9001);
			//("Value for image transformation out of bounds.\nVanishing point on horizon must be specified as a value between 0 and 1.");
		}

		$w = imagesx($aGdImg);
		$h = imagesy($aGdImg);

		// Create new image
		$ww = $w;
		if( $aMinSize )
		$hh = ceil($h * $aHorizon / ($aSkewDist+$h));
		else
		$hh = $h;

		$newgdh = imagecreatetruecolor($ww,$hh);
		$crgb = new RGB( $newgdh );
		$fillColor = $crgb->Allocate($aFillColor);
		imagefilledrectangle($newgdh,0,0,$ww-1,$hh-1,$fillColor);

		if( $aBorder ) {
			$colidx = $crgb->Allocate($aBorder);
			imagerectangle($newgdh,0,0,$ww-1,$hh-1,$colidx);
		}

		$mid = round($w * $aHorizonPos);

		$last=$h;
		for($y=0; $y < $h; ++$y) {

			$yp = $h-$y-1;
			$yt = floor($yp * $aHorizon / ($aSkewDist + $yp));

			if( !$aQuality ) {
				if( $last <= $yt ) continue ;
				$last = $yt;
			}

			for($x=0; $x < $w; ++$x) {
				$xt = ($x-$mid) * $aSkewDist / ($aSkewDist + $yp);
				if( $aDir == SKEW3D_UP )
				$rgb = imagecolorat($aGdImg,$x,$h-$y-1);
				else
				$rgb = imagecolorat($aGdImg,$x,$y);
				$r = ($rgb >> 16) & 0xFF;
				$g = ($rgb >> 8) & 0xFF;
				$b = $rgb & 0xFF;
				$colidx = imagecolorallocate($newgdh,$r,$g,$b);
				$xt = round($xt+$mid);
				if( $aDir == SKEW3D_UP ) {
					$syt = $yt;
				}
				else {
					$syt = $hh-$yt-1;
				}

				if( !empty($set[$yt]) ) {
					$nrgb = imagecolorat($newgdh,$xt,$syt);
					$nr = ($nrgb >> 16) & 0xFF;
					$ng = ($nrgb >> 8) & 0xFF;
					$nb = $nrgb & 0xFF;
					$colidx = imagecolorallocate($newgdh,floor(($r+$nr)/2),
					floor(($g+$ng)/2),floor(($b+$nb)/2));
				}

				imagesetpixel($newgdh,$xt,$syt,$colidx);
			}

			$set[$yt] = true;
		}

		return $newgdh;
	}

	// --------------------------------------------------------------------
	// _TransVert3D() and _TransHor3D() are helper methods to
	// Skew3D().
	// --------------------------------------------------------------------
	function _TransHor3D($aGdImg,$aHorizon=100,$aSkewDist=120,$aDir=SKEW3D_LEFT,$aMinSize=true,$aFillColor='#FFFFFF',$aQuality=false,$aBorder=false,$aHorizonPos=0.5) {

		$w = imagesx($aGdImg);
		$h = imagesy($aGdImg);

		// Create new image
		$hh = $h;
		if( $aMinSize )
		$ww = ceil($w * $aHorizon / ($aSkewDist+$w));
		else
		$ww = $w;

		$newgdh = imagecreatetruecolor($ww,$hh);
		$crgb = new RGB( $newgdh );
		$fillColor = $crgb->Allocate($aFillColor);
		imagefilledrectangle($newgdh,0,0,$ww-1,$hh-1,$fillColor);

		if( $aBorder ) {
			$colidx = $crgb->Allocate($aBorder);
			imagerectangle($newgdh,0,0,$ww-1,$hh-1,$colidx);
		}

		$mid = round($h * $aHorizonPos);

		$last = -1;
		for($x=0; $x < $w-1; ++$x) {
			$xt = floor($x * $aHorizon / ($aSkewDist + $x));
			if( !$aQuality ) {
				if( $last >= $xt ) continue ;
				$last = $xt;
			}

			for($y=0; $y < $h; ++$y) {
				$yp = $h-$y-1;
				$yt = ($yp-$mid) * $aSkewDist / ($aSkewDist + $x);

				if( $aDir == SKEW3D_RIGHT )
				$rgb = imagecolorat($aGdImg,$w-$x-1,$y);
				else
				$rgb = imagecolorat($aGdImg,$x,$y);
				$r = ($rgb >> 16) & 0xFF;
				$g = ($rgb >> 8) & 0xFF;
				$b = $rgb & 0xFF;
				$colidx = imagecolorallocate($newgdh,$r,$g,$b);
				$yt = floor($hh-$yt-$mid-1);
				if( $aDir == SKEW3D_RIGHT ) {
					$sxt = $ww-$xt-1;
				}
				else
				$sxt = $xt ;

				if( !empty($set[$xt]) ) {
					$nrgb = imagecolorat($newgdh,$sxt,$yt);
					$nr = ($nrgb >> 16) & 0xFF;
					$ng = ($nrgb >> 8) & 0xFF;
					$nb = $nrgb & 0xFF;
					$colidx = imagecolorallocate($newgdh,floor(($r+$nr)/2),
					floor(($g+$ng)/2),floor(($b+$nb)/2));
				}
				imagesetpixel($newgdh,$sxt,$yt,$colidx);
			}

			$set[$xt] = true;
		}

		return $newgdh;
	}

	// --------------------------------------------------------------------
	// Skew image for the apperance of a 3D effect
	// This transforms an image into a 3D-skewed version
	// of the image. The transformation is specified by giving the height
	// of the artificial horizon and specifying a "skew" factor which
	// is the distance on the horizon line between the point of
	// convergence and perspective line.
	//
	// The function returns the GD handle of the transformed image
	// leaving the original image untouched.
	//
	// Parameters:
	// * $aGdImg, GD handle to the image to be transformed
	// * $aHorizon, Distance to the horizon
	// * $aSkewDist, Distance from the horizon point of convergence
	//   on the horizon line to the perspective points. A larger
	//   value will fore-shorten the image more
	// * $aDir, parameter specifies type of convergence. This of this
	//   as the walls in a room you are looking at. This specifies if the
	//   image should be applied on the left,right,top or bottom walls.
	// * $aMinSize, true=make the new image just as big as needed,
	//   false = keep the image the same size as the original image
	// * $aFillColor, Background fill color in the image
	// * $aHiQuality, true=performa some interpolation that improves
	//   the image quality but at the expense of performace. Enabling
	//   high quality will have a dramatic effect on the time it takes
	//   to transform an image.
	// * $aBorder, if set to anything besides false this will draw a
	//   a border of the speciied color around the image
	// --------------------------------------------------------------------
	function Skew3D($aHorizon=120,$aSkewDist=150,$aDir=SKEW3D_DOWN,$aHiQuality=false,$aMinSize=true,$aFillColor='#FFFFFF',$aBorder=false) {
		return $this->_Skew3D($this->gdImg,$aHorizon,$aSkewDist,$aDir,$aHiQuality,
		$aMinSize,$aFillColor,$aBorder);
	}

	function _Skew3D($aGdImg,$aHorizon=120,$aSkewDist=150,$aDir=SKEW3D_DOWN,$aHiQuality=false,$aMinSize=true,$aFillColor='#FFFFFF',$aBorder=false) {
		if( $aDir == SKEW3D_DOWN || $aDir == SKEW3D_UP )
		return $this->_TransVert3D($aGdImg,$aHorizon,$aSkewDist,$aDir,$aMinSize,$aFillColor,$aHiQuality,$aBorder);
		else
		return $this->_TransHor3D($aGdImg,$aHorizon,$aSkewDist,$aDir,$aMinSize,$aFillColor,$aHiQuality,$aBorder);

	}

}


?>